How do you correctly position a ball joint?

[aclwalker 3]

Suppose you have a VR6 Corrado, and you have no confidence that one of the ball joints at the front is positioned correctly on the control arm. Imagine you've had problems with a mechanic in the past and your inspection is pointing you to this! Or imagine you have a totally new control arm which obviously has no prior markings.

 

How do you position the ball joint correctly on the control arm with the 3 bolts and welded nut plate? Everywhere just says "mark the position before removing and refit to marks", but clearly this doesn't work if you think its wrong in the first place or if you are fitting a new control arm.

 

Why is the position variable in the first place, if you are supposed to always put it back in the same position? Why is it not designed such that it is not possible to fit it too far out or in?

 

Incorrect positioning of the ball joint has implications for the camber setting and could also potentially make the wheel too close to the body possibly resulting in rubbing when turning at full lock.

 

Any advice anyone?

[davidwort 0]

good question, I wondered this when doing my 16v ball joints, I believe the VW factory manual says they should not be used in an attempt to adjust camber, but I don't know if they provide precise measurements for fitting though, perhaps someone with the Bentley can look it up.

I just made sure both side were approx the same (and approx where the old ones were fitted) and then set the camber and did the alignment on the car, it all set up fine and it feels perfectly balanced and I've had no uneven tyre wear :shrug:

[aclwalker 3]

good question, I wondered this when doing my 16v ball joints, I believe the VW factory manual says they should not be used in an attempt to adjust camber, but I don't know if they provide precise measurements for fitting though, perhaps someone with the Bentley can look it up.

I just made sure both side were approx the same (and approx where the old ones were fitted) and then set the camber and did the alignment on the car, it all set up fine and it feels perfectly balanced and I've had no uneven tyre wear :shrug:

Well, exactly, they shouldn't be used to adjust camber, but if you can't position them correctly through them being wrong already, or due to fitting a new control arm then camber adjustment is what you will achieve whether you like it or not!

 

I have checked Bentley and it, rather unhelpfully, simply says to mark and refit!

[davidwort 0]

so I guess what I did is all you can do, make sure both sides measure the same and roughly in the centre of the fixing or about where the old ones were in the old wishbones, you'll soon find out when it's all back together and you can't get any negative camber at all :scratch:

 

I think if you look at the layout of the suspension and geometry, that they will have far less of an effect on camber than the strut bolts.

[souron 0]

i would assume a competent mechanic with an alignment machine should be able to get you close to where they should be

[aclwalker 3]

i would assume a competent mechanic with an alignment machine should be able to get you close to where they should be

I doubt any mechanic would ever adjust a balljoint position to set alignment or camber. They would just assume that it was correct. They would only maybe investigate (if they can be bothered) if they can't get enough adjustment and then suspect the balljoint is in the wrong position.

 

However, if like me you either know or strongly suspect that the balljoint is in the wrong position, an alignment and camber setting is not going to correct it for you, because they will simply assume its correct and adjust the strut to compensate for any incorrect balljoint setting.

 

I just wish I could find out the criteria for positioning the balljoint with all new components so that I can eliminate a variable.

[Riley 0]

Another great bit of design/engineering on the corrado eh :lol: :gag:

 

Id like to know the 'mechanically correct' position too. As if half the mechanics out there would even think of marking a ball joint before removing it.

 

Neil.

[andy 0]

If you have no reference to work with, I'd position it in the middle of its adjustment, you're only talking +/- mm from the centre point, the rest can be adjusted in the usual way (on the 2 bolt, strut to hunb clamping arrangement) during proper 4 wheel allignment. I agree though the whole design is daft :?

[davidwort 0]

does it not allow for alignment with the rear wheels though?

thinking about it, the camber setting from the strut/hub can't affect the track, and the tie rods only affect toe,

so in theory, the small amount of movement on each ball joint allows you to align each front wheel with the back on that side of the car. No?

[Album56 0]

If its a track rod ball joint thats been replaced then it adjusts the toe & I was advised many years ago when working on a mini that front wheel drive cars should have the front wheels parallel to each other & the car. Had my G60 checked & re-aligned after main dealer had replaced front hub bearings

at the local tyre dealer that has a laser wheel alignment machine & what a difference, the main dealer had the car for an extra day & made a right mess of it, but after the "Hunter" machine was used it was perfect.

[was8v 0]

does it not allow for alignment with the rear wheels though?

thinking about it, the camber setting from the strut/hub can't affect the track, and the tie rods only affect toe,

so in theory, the small amount of movement on each ball joint allows you to align each front wheel with the back on that side of the car. No?

 

 

Only by a very small amount. I'd be very surprised if the tolerances on parts like rear beams, bushes and front suspension components are made to such a small tolerance.

 

I'd stick it in the middle of its adjustment and then get the alignment set up by a trusted place (not just any tyre monkey).